[media] gspca_sonixb: Remove querymenu function (dead code)

We forgot to remove that when sonixb was converted to the control framework.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>